Conventionally, as an art of this field, there is JP-A No. 2003-181379. A vibration motor disclosed in the publication includes a core having coils wound on coil parts and a weight disposed between the coil parts. The weight has weight pieces having a fan-shape, which are decoupled from above and below. The upper weight piece is inserted between the coils from above and the lower weight piece is inserted between the coils from below and the upper and lower weight pieces are then connected by a rivet. In addition, the weight is covered by a cover member made of an electrically insulating material, so that insulation inferiority between the coils and the core is prevented.